Crack identification through scan-tuning of vibration characteristics using piezoelectric materials

Abstract

This research develops a frequency-based methodology with a scan vibration tuning process for crack identification in beam-type structures coupled with piezoelectric materials. Piezoelectric sensor and actuator patches are mounted on the surface of the host beam synchronously to generate feedback excitations for a tuning process by applying a feedback voltage output from the piezoelectric sensors. The feedback excitations can adjust the stiffness at local section of the beam covered by piezoelectric patches so as to tune its natural vibration mode shapes to amplify the natural frequency change due to the existence of the crack. Piezoelectric patches located at different positions of the beam are activated one by one to realize the scan-tuning process. The crack is identified since the natural frequency change is magnified by the piezoelectric sensor and actuator located at the crack position. Theoretical and finite element models of the scan-tuned beam structures coupled with piezoelectric materials are established. From simulation results, the crack existence and location can be effectively detected through the scan-tuning process with 25% natural frequency change due to a crack located at the middle of the beam. Further parameter studies are conducted to study the effects of the crack location and size on the detection sensitivity.

Modal analysis of cracked beam with a piezoelectric layer

“…where u(x, z, t), w(x, z, t) denote axial and transverse displacements at arbitrary point in the beam; u 0 (x, t), w 0 (x, t) -the displacements in the beam's mid-plane (z = 0) and ε x , σ x are strain and stress in cross-section at x. material. Namely, Zhao et al [27] proposed an interesting technique for crack identification in beam-type structures by natural frequencies using coupled pairs of piezoelectric sensor and actuator.…”

“…Recently, dynamics of cracked structures with piezoelectric patches [25,26] has attracted a special attention of researchers to develop an efficient method for crack identification using piezoelectric material. Namely, Zhao et al [27] proposed an interesting technique for crack identification in beam-type structures by natural frequencies using coupled pairs of piezoelectric sensor and actuator.…”

Novel Damage Detection Tool Based on Load Path Analysis Using Ustar (U*)

“…where k and k are the stiffness of the original structure and the modified structure with constrained test/measure point as described by (7). The stiffness can be obtained from the linear regression of the force-displacement curves at the loading point.…”

“…Jiang et al [4], [5] proposed another method to enlarge the damage-induced frequencyshift by using a tunable piezoelectric transducer circuitry. More recently, piezoelectric materials were employed by Zhao et al [6], [7] to alter the vibration mode shapes of beams via feedback scan-tuning. Frequency-shift was significantly magnified while the piezo-patch at the location of the damage was activated, giving it the potential of locating the damage.…”

A cantilever-structure triboelectric nanogenerator for energy harvesting and defect detection via long short-term memory network

“…Aiming at defect detection of cantilevers, Zhao et al. 47 used a feedback voltage output of piezoelectric sensors to change the stiffness at local section of the beam and amplify the natural frequency change of the beam caused by cracks, so defects can be easily identified. Deng et al.…”